Dental mold.



B. C. MOLL.

DENTAL MOLD.

' APPLICATION HLEDTEB. 19, 190s.

A1 -037,962 Patented sept. 10,1912.

. UNITED sTATEs PATENT oEErcE. y

BERNHARD c. Mom., or CHICAGO, ILLINoIs.

DENTAL Mom).l

Specification of Letters lllatent.v Patented Sept. i0, 1912. i

Application 'iqled February 19, 1908. Serial No. 416,666.

To all whom 'it V'may concern:

Be it known that I, BERNHARD C. MOLL,l a citizen of the United States ofAmerica,-

and resident of Chicago, Cook county, Illinois, have invented a certainnew and useful nia be made to conform closely to the walls of he cavityand at the same time may be made yof greater density than those made bythe ordinary methods.

vA further object is-the production of a mold by the use of which thefillings above referred to may be cheaply manufactured.

A further object is the production of a cast filling far superior tothose formed by the usual processes.

These and such other objects as may hereinafter appear are attained bymy device, an embodiment of which is illustrated in the accompanyingdrawing, in which- Figure l represent-s -a perspective view of myimproved sprue former. Fig. 2 represents a cross-section of a flask withmy improved sprue. former .in position. Fig. 3 represents a sectionalview through the center of the mold after the sprue former has beenwithdrawn from the flask.

Like letters of reference indicate like parts in the several gures ofthe drawing.

Referring now by numeral t-o the accom! panying drawings-41` representsan ordinary ask generally comprisinga section. of tubing; 5 representsthe investment material; 6 represents the sprue former comprising a baseportion 7 with an upwardly eX- vtending pointed end 8. Seated on thisend is the pattern of wax or some like material 9. The flask is adaptedto rest yon a shelf or table 10.

In the use of my device, the dental cavity is first properly prepared,care being taken that there are no rentrant cavities or overhangingporti-ons. The wax is then forced into the cavity, care being taken -tohave the material fill :every portion of the cavity. The patient! thenbites on thev Waxin order to secure a proper surface to the filling. Thewax pattern is then withdrawn, the surplus portion removed, and thepattern mounted on the point of the sprue former'. This sprue former isformed with abase portion 7 in order that the former may stand uprightupon the table or stand 10. The flask 4 is then placed over the sp'rueformer with the pattern therein, and the investment material pouredwithin the mold. Theconsistency of the investment material is such thatas the material riseswithin the flask, if care is exercised -in thepouring, no air bubbles will form between the sides of the pattern andthe body of the material. In some instances, however, I prefer to dustthe surface of the pattern lwith powdered investment material-beforeplacing it within the flask. After the investment material has coveredthe pattern to a sufficient depth.- generally one-fourth to half aninchthe flask is allowed to stand until the material becomes properlyset. The flask is then turned end for end and the sprue former 6removed, leaving a cavity 11 (shown in Fig. 3) terminating in the sprue12. The fiask is then subjected tov heat, and the wax pattern absorbed,leaving a hole or mold 13 of the exact configuration of the pattern 9.The gold 'or other materia-l from which the filling is to be made isthen placed in the cavity 11 and melted in any wellV known manner. l

A cover 14 of any desired form 'or shape, to which is connected a pipe15 leading' to a compressed air supply, 1s then placed over the iask andair pressure turned on. As soon as air pressure is turned on, the moltenmetal within the cavity 11 is forced through the sprue l2 into the mold13. Suiiicienty molten material is provided to completely fill thecavity and generally a portion or all of the sprue. When castings are'formed in the ordinary manner, it often happens that the article cast isfull of minute blo'w holes, while at the same time, unless pressure isapplied, the molten material rarely reaches lthe inner portions of themold, especially in the case of molds for dental cavities. This, ofcourse, prevents the casting from being a perfect t, and allows theaccumulation `of moisture and material between the walls of the cavityand the lling afterthe same is in place. Decay is often apt to set in,with'th'e result that the entire tooth again becomes decayed, requirinnew treatment. By the use of compresse air, however, in Which the moltenmaterial is forced Within the mold, so that it reaches every portionthereof, the result is that the casting is remarkably free from blowholes, and is also a perfect replica of the mold itself.

The elimination of the blow holes forms a casting 'of much greaterdensity than those obtained by the ordinary method of filling, and givesa new article of manufacture in the shape of a cast lling which can beinserted in the cavity after the same has been coatedwith the` cement sothat the tooth is filled in a much more satisfactory manner than by theuse of any /ot-her method or process heretofore employed.

Attention is called to a companion application, filed herewith of evendate, Serial No. 416,667, covering a machine for manufacturing dentalfillings.

While I have illustrated and explained this device and process asespecially applicable for use by dentists, it is understood that I donot limit myself to such use, as castings of any size or of any desiredmaterial may be formed by the use of my im- Droved device and process.

I claim: Y

1. In a device of the class described, the combination with a flaskhaving a sprue channel therewithin, a cover for said flask, and meansfor passing air or gas under pressure through said cover and channel,and means for diffusing said air or gas before it enters said channel.

2. In a device ofthe class described, the combinationivith a flask, acover for said flask, a funnel-shaped opening in said cover, means forpassing air or gas under pressure through said cover, and a perforatedplate in the lower part of said opening to diiiuse said air or gas.

In a casting machine, an investment flask, a cap for said flask havingan enlarged opening in the lower portion thereof, a tube passing throughthe upper part of said cap and terminating in an enlarged head in theopening of said cap, and means for passing air or gas through` said tubeor cap.

Signed by me at Chicago, Illinois, this 24th day of October, 1907.

BERNHARD C. MOLL.

Witnesses SARAH LEWIS, ALBERT J. SAUSER.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents,

' Washington, D. C.

